Effect of Aluminum on Fabrication of Ti3SiC2 by Mechanical Alloying and Spark Plasma Sintering

Abstract:

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In the present study, we fabricated high purity and electrically machinable Ti3SiC2 ceramics by
mechanical alloying and subsequent spark plasma sintering. The effect of a trace amount of Al on these
synthesis processes was examined. Our results showed that Ti3SiC2 could be synthesized by high energy
milling. Spark plasma sintering of mechanically alloyed powder at the temperatures of 1000-1200°C
produced nearly single-phased Ti3SiC2 materials. The purity of the sintered Ti3SiC2 bulk was remarkably
increased by addition of a small amount of Al. Ti3SiC2 with a purity of 99.3 wt% and a relative density of
98.9% was obtained by mechanical alloying and subsequent spark plasma sintering from a starting
mixture composed of n(Ti) : n(Si) : n(Al) : n(c) = 3 : 1 : 0.2 : 2 at 1100°C.

Abstract: Iron (Fe)-tin (Sn) intermetallics were synthesized by using two different routes. These two routes had a common synthesis step, in which Fe powder (19 wt. %) was mechanically alloyed with Sn powder (81 wt. %) for 25 h under argon atmosphere. The mechanically alloyed powders were then treated with different heating routes. In the first route, the compacts of the mechanically alloyed powders were sintered at different temperatures for different times. It was found that the FeSn2 content increased with increasing temperature and time. There were small traces of Fe, Sn and FeSn found in the sintered materials. In the second route, the mechanically alloyed powders were plasma-sprayed using different currents of 300, 400 and 500 A. It was found that the porous coatings produced by plasma sprayng consisted of mixed Fe, Sn, FeSn2, SnO, FeO and Fe3O4 for all employed currents.